/Engine/Plugins/Importers/USDImporter/Source/USDExporter/Public/USDConversionBlueprintLibrary.h
Returns how many total Unreal levels (persistent + all sublevels) will be exported if we consider LevelsToIgnore
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="World utils") static int32 GetNumLevelsToExport ( [UWorld](API\Runtime\Engine\Engine\UWorld) * World, const [TSet](API\Runtime\Core\Containers\TSet)< [FString](API\Runtime\Core\Containers\FString) > & LevelsToIgnore )